Fluorescent light fixture



April 1950 E. B. HALLMAN FLUORESCENT LIGHT FIXTURE Filed July 20, 1945 bade/Z201 Emc. B.HALLMAN Patented Apr. 25, 1950 FLUORESCENT LIGHT FIXTURE Eric B. Hallman, Philadelphia, Pa., assignor to Electric Service Manufacturing Company, Philadelphia, Pa., a corporation of Pennsylvania Application July 20, 1945, Serial No. 606,184

2 Claims.

This invention relates to lamp sockets and more particularly to an improved construction of socket for double-ended tubular discharge lamps, such as fluorescent lamps.

Heretofore and prior to the present invention, tubular discharge lamps of the type having a pair of spaced contact or terminal prongs at their opposite ends have depended for their securement in the sockets respectively provided for the pronged ends thereof upon the frictional engagement of the terminal prongs with the spring metal contact elements conventionally employed in the sockets. This has proved not to be entirely satisfactory, particularly in the case where the lamp is subject to vibration, as where it is installed as a lighting fixture in railway vehicles, buses and other such conveyances.

Accordingly, it is among the principal objects of the present invention to provide as an auxiliary to the lamp socket means independent of the lamp prongs for supporting the lamp in position, thereby relieving the prongs of the weight of the lamp and at the same time insuring the lamp against its accidental displacement from its sockets even when subject to the most severe vibration. v A further object is to provide means in association with the conventional sockets fora tubular discharge lamp which are operative to releasably lock the lamp in supported position between its end sockets, said means being simple and inexpensive in design and construction as well as readily operable to release the lamp from its sockets for purposes of replacement, maintenance and repair.

Other objects and advantages of the invention will appear more fully hereinafter, it being understood that the present invention consists in the combination, construction, location and.

relative arrangement of parts all as described in detail hereinafter, as shown in the accompanying drawings and as finally pointed out in the appended claims. In the said accompanying drawings, Figure 1 is an exploded view in perspective showing the lamp-supporting means of the present invention as employed in a fluorescent lighting unit of the type such as might be used more particularly in the interior of passenger vehicles;

Figure 2 is an elevational view of the lamp socket showing in association therewith the lamp supporting means in unoperative position;

Figure 3 is a view similar to Figure 2 but showing the lamp supporting means rotated into operative position;

Figure 4 is a sectional view taken substantially along the line li-4 of Figure 2;

Figure 5 is a sectional View taken substantially along the line 5-5 of Figure 3;

Figure 6 is a perspective view of the auxiliary lamp supporting means per se; and

Figure '7 is a perspective view of the said means shown operatively associated with the lamp socket.

Referring now to the drawings and more par ticularly to Figure 1 thereof, it will be observed that the present invention has been shown as applied to a fluorescent lighting unit of the type suitable for installation in a passenger vehicle, although it is to be understood, of course, that the present invention is adapted for use gen erally in all types of fluorescent lighting units having end sockets for reception of the pronged ends of the lamp. In the unit illustrated in Figure 1, these end sockets are designated by the reference numeral It and are respectively mounted upon the end support members I l--l I of the unit between which extends a suitable reflector or shield 12. The tubular discharge lamp I3 is of the well-known conventional type having at each of its opposite ends a pair of contact prongs I l-l4, each pair of which is received within a corresponding pair of spring contact elements l5l 5 suitably secured respectively within the open-ended slots |6I6 of each socket it. i

In accordance with the principles of the present invention, these sockets H) are each of circular outline and are respectively secured to the end supporting brackets H-Il of the lighting unit by a pair of screws ll|1 or the like, the rear face of each socket being maintained free of its supporting bracket by spacing washers l8-l8 of insulating material which serve also to insulate the socket from its supporting bracket. In its properly mounted position, the open ends of the slots IFS-it of the socket extend downwardly so as to facilitate insertion and removal of the pronged ends of the lamp into the socket from the bottom of the lighting unit, the terminal prongs |4--l4 of the lamp being frictionally en gaged by the spring contact elements 15-45.

To prevent unintentional or accidental displacement of the lamp from its sockets, each of the latter is provided with a lamp-retaining collar I9 of the form most clearly shown in Figures 6 and 7. This collar is in each case provided with a circumferentially continuous body portion 20 having at rear edge an inwardly turned flange 2| which fits against the rear face of the circular body portion of the socket [0 at the same time that the annular body portion 20 of the collar embraces the rim of the socket. The fit of the collar l9 upon the body of the socket is such that the collar is free to be rotated relatively to the fixed socket, the rear opening 22 of the collar, as defined by the circular edge of the radial flange 2|, being sufficiently large to provide for such free projection therethrough of the spacer, washers l'8-- 'l8 and the mounting screws 'lllT as not to interfere with the rotation of the collar 19 relatively to the socket with which it is as sociated.

The annular body portion 20 of the rotatable collar is notched, as at 23,'to 'reduc'ethe'widthof said portion sufiiciently to permittheirein-l sertion and removal of the lamp prongs into and out of engagement with theirassociated spring contact elements in the socket when the collaris rotated into the positions shown in Figures 1', 2

and 4. It will be noted that the notch 23 in the from-its-"p'osition shown in Figures 2 and 4 the open ends of the socket slots lli-l6 are closedby-the'annular wallof the collar and so prevent dropping of the end of the lamp out of'it-s socket should the prongs l4"l4 become free of their spring contact elements 5---l 5.

AsthOstclearly appears in Figures 6 and '7, the

annular wall of the collar I9 is provided along its frontal edge with an outwardly turned flange 24 which terminates in a-semi-eircular rim portion 25* extending forwardly of and in coaxial relation to the annular body portion 2?} of the collar. This semi-circular rim portion 25 is located diametrically opposite the notch 23 and lsof a" radius which'so corresponds to that o'fthe" end of the tubular lamp lB-that-When the collar is rotated into its position shown in Figures 3 and 5, said rim portion 25" affords a'posi'tive arcuatesuppbrt for 'thelamp end independent of the" interengag'ed prongs and contact elements} Preferably, butfnot necessarily, the outer rim portion 25' of the rotatable collar [9 is provided at its opposite 'end-s'with radially extending terminaktabs 26 -46 to facilitate rotation of the collar 'from its inoperative position shown in Figuresz ahd4 into its operative, lamp support ing position sho'w'n in Figures 3 and 5. It'will be apparent that when in' this latte'r'p'ositi'on the collar l jretains' the" tubular lamp in position against displacement from its socket even when the lighting unitis subjected to the most severe vibration.

The lamp supporting collar of the presentin vention is of simple construction andis readily" a'Xis'of'tlie-lainpl.

4 mounted upon the socket, with which it is associated by slipping it over the rear end thereof, the collar itself being then retained in position upon the socket when the latter is secured to its mounting bracket II as shown and hereinbefore described.

It will be, understood, of coursa that the presventibnj is suscep e -of various changes and fhodific'aftionswhich'inay be rfiad from time to time without departing from the real spirit or general principles thereof, and it is accordingly int'hded to cla'im the invention broadly, as well as V specifically, as indicated by the appended Wha f'ajs new and useful is:

l. Afitting ior a tubular discharge lamp of the typ havihg end terminal pins for engagement with the contact elements of a socket with which saij lamp is associated, said fitting comprising a circumferentially continuous annular member rota ply carried by; the socket and having a s 1 11sof a radius sufficiently large d of the lam'piriime diately adjoining"- the "t, said run" extending iiy' be ii the lamp ad ihin'g 'or front face lying the rear face or the socket.

, "2, A suppprtiii fitting for a tubu ar disc arge lamp adapted for operative association with s;

lampsocket of theftyp'e savings. pa r or iaterauy spaced opeiiserid'ed. slots for receiving theconta'cj; prong of themes, .saicl fitting being r'otatabii carried by thes'ockfet and including a c rg cunirerentians renditions r'im' having" a" ortion" thereof cu't" ou'ttoi provide." a notch through which theterrninal rongs or thela'irip may 'rree1y pass when the" lamp ser't'ed hto the socket, said ririi'bei'rigf furtherprovided at the side; thereo diametrically opposed? to said notch with ah at:

cuate flange extendingfaxially' beyond the outer face of the socket and of a radius sufficient to' iste as asisiemgs es r. extending circumferentially about the rim of the 'laiiipimnie'diately through an arc of suificient extentto expos'the' lamp prong-receiving slots. of the socket when g flange, above? the longitudinal rate 12 IiALLiiANi semester's CITED The following references are of record in thefile *of this patent:

FOREIGN PATENTS or'inariyi'ni Oct. 1, 1937 y 't'urnedf annular flange" over as f the socket, said'not'c'h' tated to position the said arc'uate" Country Date Gr'r aany July 3, 1928" qrma y" June 3, 1930 

